The putter is the golf club that should be used most in a round of golf. Half the strokes, or very nearly half the strokes are laid down for the putter in regulation round of golf. It could be argued that the putter should therefore be the most precise club used by the golfer, and that all efforts should be made within the rules of golf to ensure that the putter provides optimum feel, and provides optimum ease of alignment for the golfer.
Reference is made to the "sweet spot" of the golf putter. The sweet spot of a golf club, or as in the present case a golf putter, is well known to those who are familiar with the game of golf. It is the area on a club face which should come in contact with the ball in order to give the greatest and straightest distance or flight to the ball and the best feeling.
The sweet spot is usually a relatively small area surrounding the intersection of a line normal to the ball striking face, which line passes through the centre of percussion of the club comprising the club head, shaft and grip. Where the striking face has a loft angle the sweet spot is the small area surrounding the intersection of a straight horizontal line with the ball striking face which passes through the centre of percussion when the sole of the putter head is on a horizontal surface. In a putter, there would not be much variation in the location of the sweet spot if a normal or straight horizontal line were considered because the loft angle is usually small and the periphery of the sweet spot tends to be ill defined. In a putter having right and left handed striking faces it follows that there are right and left handed sweet spots.
It is of great importance to the golfer to strike the ball at or very near the centre of the sweet spot; and particularly in the case of the putter, it is most important that the ball striking face of the putter head is at right angles to the selected line of the putt at the point of impact. This invention assists the golfer to achieve these aims.
One drawback with blade type putters is that it is difficult to align the axis of the shaft to pass through the centre of percussion or the sweet spot of the putter head because the hosel is located at one end of the blade.
There is another drawback with blade-type putters and this concerns additional costs of manufacture because different clubs need to be manufactured for left and right handed players. Therefore separate patterns, separate dies, separate jigs, and separate tooling is required to manufacture most right hand and left hand blade type golf putters. This is because most blade type golf putters, which are distinct from centre-shaft type golf putters, are not symmetrical about their vertical toe to heel axial plane, and preferred embodiments of the invention overcome this problem.
Another drawback with current blade type golf putters is that they do not facilitate alignment of the putt. Some golfers tend to be distracted because of the shape of the back of the blade. The back of the blade may include a flange at the lower portion of the blade and/or a protruding shape or shapes that are not in line with the top edge of the ball striking face of the putter head which the golfer uses to square the putter to the intended line of the putt at impact. Preferred embodiments of the invention also overcome this drawback.
Further, a golfer may be distracted when lining up a putt, and when putting, by non-symmetrical and protruding hosels and heels of the putter head. Preferred embodiments of the invention also overcome this drawback.
A number of published patent specifications have dealt with the alignment of the axis of the shaft with the centre of gravity of the head or centre of percussion of the head, see for instance U.S. Pat. No. 2,926,913, Australian Patent Specification Nos. 466,553 and 449,540. These documents do not, however, address the manner in which those principles could be applied to a golf putter particularly a blade type of putter.
British Patent No. 14608 relates only to a single faced blade type putter with a configuration whereby the hosel basically extends from the heel of the blade without any stipulation regarding the axis of the shaft passing through the centre of percussion, or the axis of the shaft passing through a point in line and mid-distance between the sweet spots, or the axis of the shaft passing through a point in line and mid-distance between the centres or centroids of the sweet spots.
Other specifications such as British Patent No. 382046, U.S. Pat. Nos. 786,268 and 4,592,552 and Australian Patent Specification No. 79368/75 are concerned with the design of putters but none of them specifically addresses the problem of having a blade type putter in which the axis of the shaft is aligned with the centre of percussion.